ubuntu – General Quesiton about where to mount a RAID VD volume, etc

We recently re-installed UBUNTU on a system that had UBUNTU system on a 500 GB RAID VD (1 slot) and DATA on another RAID VD (5 slots, RAID 5). After booting up the new system the RAID VD automatically mounted on /media, rather than on /mnt, which is where it was apparently setup before. Just wondering if there is a particular convention for that because we might end up installing a new system on the system disk periodically, or restoring from a system disk image.

I don’t think it makes much difference as to where things are located since the DATA volume has some Docker Containers and DATA that are pretty much self-contained and recovered just fine after installing the new system.

The RAID isn’t exactly “removable” media, but sort of, and I guess the system treats it as such.

Can I mount a ring flash to the kit lens of the Olympus OM-D E-M10 Mark II?

No, on this particular lens. The ring flash would use the filter thread which is positioned around the front lens. The ring flash would add weight on the tip of the lens.
Since the lens is a small motorized zoom lens, I would not trust it to support a ring flash. The motor and zooming mechanism risks premature breakage, even if not activated during the use of the ring flash. I would use a ring flash on a prime lens or on a sturdier zoom lens, mechanically speaking.

On flash compatibility

A flash in manual mode (no TTL, no HSS) can work on any camera as it only uses the center pin to trip the flash. However, if you want TTL/HSS compatibility make sure the flash socket is made for Olympus OM-D E-M camera. A manual flash won’t be a problem for most situations. See this topic covering the problem in much more depth.

My advice

As for beginning into flash photography, i would advise to choose an off-camera system (wired or wireless). And experiment with various flash modifiers. Bare flash light is not always a desirable light. Cheap flash modifiers can be made for a couple of $€. Free DIY plans are available all over the web. If you are not into DIY, it will be more expensive (sometimes more than a new flash!). What you want to fiddle with : bounce (cards or walls), honeycomb grid (of various angles), diffuser (various forms), beauty dish, barn doors, snoot + honeycomb… You can even combine them, sky is the limit !

The advantage of this strobist style is that you can dissociate the camera and flash placement relative to your subject. Also, you can change the type of lighting you want on the cheap with flash modifiers.

If you wan to stay on ring flash, stick with xenon tube flash (avoid led) for better light quality. To widen your search, you might also consider twin flash systems. They produce similar lighting conditions than a ring light. The power of a flash is determined by its Guide Number (GN). For a better usability, try to get a flash with a Guide Number around GN60 or more. Lesser GN are more targeted at macro and proxi photo.

My opinion on brands

Yongnuo is one of the cheapest brand of flash. Expect sample variations in lifespan and aging color cast after some years. However, it can be a good source for trying out something new on the cheap and choose a better flash system later. They have a ring flash YN14EX but only for Canon it seems. Maybe other makes are supported on the new version II.

I own Godox. For me, Godox is the best brand for cheap but reliable and qualitative flash system. I use a v685 flash with a X1-Pro wireless transmitter. The AKR1 modifier kit + S1R adapter allows me to have some magnetic modifiers ready to use under a minute. However, I also do some other modifiers in DIY fashion. In some situation, I would like to have a second v685. I might buy another one in the future to complete my kit or an AD200. They have a few ring flashes (a big one for studio: AR400, a normal one: ML150).

Nissin delivers compact but powerful flashes. Best sized for smaller mirrorless cameras. However, that comes with a price (2 to 3 times Godox price). They have good wireless controllers with physical dials (best if you want to set it without looking). Their ring flash (https://www.nissindigital.com/mf18).

Paul C. Buff make pro grade lighting equipment that not so costly. Their ring flash Alienbees ABR800 is dope with a hand grip and a strap. I would buy one if I have to get pro.

diskutil – Script to mount exfat drive

hope you are doing great.
I´m using a Macbook pro 2019 with Big Sur and I have all my photos and videos in a external drive formatted in ExFat.
Each time I have to mount the disk I need to run this steps

sudo pkill -f fsck
diskutil list
sudo umount /dev/disk2s1
sudo mkdir -p /Volumes/disk2s1
sudo mount_exfat /dev/disk2s1 /Volumes/disk2s1

Up to this point, no biggie, is a little tedoius so I wanted to create a script to do this.
My main question here is:

When I do diskutil list disk can be mounted on /dev/disk2s1 or /dev/disk3s1

nachogon@Morrowind ~ % diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *251.0 GB   disk0
   1:                        EFI EFI                     314.6 MB   disk0s1
   2:                 Apple_APFS Container disk1         250.7 GB   disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +250.7 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD - Data     12.3 GB    disk1s1
   2:                APFS Volume Preboot                 593.1 MB   disk1s2
   3:                APFS Volume Recovery                1.2 GB     disk1s3
   4:                APFS Volume VM                      2.1 GB     disk1s4
   5:                APFS Volume Macintosh HD - Datos    147.4 GB   disk1s5
   6:                APFS Volume Macintosh HD            19.4 GB    disk1s7
   7:              APFS Snapshot com.apple.os.update-... 19.4 GB    disk1s7s1

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *4.0 TB     disk2
   1:       Microsoft Basic Data Elements                4.0 TB     disk2s1

Is there any way to grep the diskutil so I can find the disk by name (Elements) so I can assign a variable to the disk identifier

Thanks in advance for any help.

2020 MacBook Pro won’t mount WD external hard drive

It’s formatted HPS+. Mounted fine yesterday (and for a long time before that). Now, the light on the drive blinks on-and-off and it sometimes briefly shows up in the output to diskutil list as /dev/disk3. I’ve tried diskutil eject disk3 and similar variants.

The drive automatically mounts on linux without issue.

I do not see fsck running (I checked with ps auxw and top from a terminal). I did not find any interesting log messages via the Console program.

We had trouble about a year ago. Apple support recommended upgrading the OS and I think that worked. We also bought a second cable for the external drive, but ended up not needing it. I just tried the second cable and it didn’t make a difference. There was an upgrade OS available and we tried that after talking to Apple support this time, but it didn’t make a difference. The drive mounts fine on a ~2016 Mac Air.

Passive Sony/Minolta a/af mount Stabilization

What do you mean by active and passive stabilisation?

The A-mount is used on older Minolta Maxxum/Dynax/Alpha SLR/DSLR cameras, and on newer Sony Alpha DSLR/DSLT cameras. Stabilisation, if available, for this system has always been implemented as in-body stabilisation – where the sensor moves. It was introduced with the Maxxum 7D DSLR in 2004, and was marketed as ‘Anti-Shake’. Sony calls it ‘SteadyShot Inside’. There are no A-mount lenses with any in-lens stabilisation technology.

Sony also has the E-mount, with some E-mount lenses having in-lens stabilisation, but that’s a different kettle of fish. E-mount lenses are not compatible with the A-mount, even with an adapter, so you can disregard them for your scenario entirely.

mount – Dock is stopping me from unmounting a hard drive

I just upgraded to Catalina and am using an external drive as a system drive and need to unmount my internal drive, but I can’t. I try sudo diskutil umount /Volumes/Macintosh HD/ and it asks for my password, tries, then tells me:

Volume Macintosh HD on disk0s2 failed to unmount: dissented by PID 2793
(/System/Library/CoreServices/Dock.app/Contents/XPCServices/com.apple.dock.
extra.xpc/Contents/MacOS/com.apple.dock.extra)
Dissenter parent PPID 1 (/sbin/launchd)

When I use ps aux to find out about PID 2793, here’s the appropriate information:

hal               2793   0.0  0.1  5253644  34068   ??  Ss    1:06AM   0:00.14
/System/Library/CoreServices/Dock.app/Contents/XPCServices/com.apple.dock.extra.xpc
/Contents/MacOS/com.apple.dock.extra

The only app (and I checked with lsof) that is using anything on that drive is the dock – and it’s using the iTunes icon. I found that out with lsof, here’s the related output line:

com.apple 2793  hal  txt       REG                1,2      23760             2640732
/Volumes/Macintosh HD/Applications/iTunes.app/Contents/PlugIns/iTunesDockTile.docktileplugin
/Contents/MacOS/iTunesDockTile

That confirms that the only app using anything on that internal drive is the Dock and that the only file being used is the iTunesDockTile. When I first saw this, I removed Apple Music from the Dock, but it still wants that tile and, rather than getting it from the external drive, that is the system drive, it’s using the one on the old internal drive.

I tried killall dock; sudo diskutil umount /Volumes/Macintosh HD and get the same message as above. (I hoped that it would unmount the drive while Dock was restarting and before it got a file lock.) I’ve considered just deleting that file, but I don’t know what consequences that would create.

I need to unmount that drive so I can reformat it.

Extra (probably unnecessary) details:

This is part of an upgrade from Mojave to Catalina. I tried to start the update and it wouldn’t, since my system drive was not in APFS. I had an extra drive, so I hooked it up via USB and formatted it in APFS, then used SuperDuper to copy my internal drive to the external. I upgraded the external to Catalina. My next step was going to be to reformat the internal in AFPS, then use SuperDuper again and copy everything on the external drive (Which is now a new Catalina update) to the internal drive. It appears EVERYTHING else is using the external for all system resources and the ONLY tile the Dock is not getting from the internal drive is this one iTunes tile.

So what is the best and safest way to deal with this to unmount the internal drive? I’ve considered using a forced unmount, but that doesn’t always work and can cause problems. I don’t want to just delete the tile file until I know what it’ll do or if there are unexpected consequences.

ubuntu – Encrypt home, connect via SSH, mount encrypted, resume boot of software that relies on files in home

I would like to encrypt my home folder on a remote raspberry server. I have several applications configured to start from my home folder though when ubuntu starts. If they start before my home is unlocked then writing will occur in system partitions (which they do not have a lot of space).

I wonder if there is a way to pause the bootup of some applications via systemd until the mount point exists. I do not mind manually having to ssh and do the mounting. I guess I could disable them and make a script to start these manually but I am looking for the most elegant option.

Btw, I can vpn into the network of the pi, so if there is a web interface that prompts for decrypting password at bootup and waits, that would be the most ideal solution.

dnd 5e – Do a mount and its rider share the same space?

Yes. Because what other space would you be in?

The rules for Mounts state:

Once during your move, you can mount a creature that is within 5 feet of you or dismount.

The rules say you can mount a creature, and since that naturally involves being in the same space, it is an exception to the rule that says you can’t end your move in the same space as another creature.

dnd 5e – Does a mount and its rider share the same space?

Yes. Because what other space would you be in?

The rules for Mounts state:

Once during your move, you can mount a creature that is within 5 feet of you or dismount.

The rules say you can mount a creature, and since that naturally involves being in the same space, it is an exception to the rule that says you can’t end your move in the same space as another creature.

cp – Safest way to move a mount point that is a parent of other mount points on Linux to a new physical device

I goofed up and /var/lib/kubelet was not mounted on a server. So it was on the root. I noticed this and I want to fix it. I did the stupid thing and just tried to stop the associated services (kubelet), rename the existing directory to /var/lib/old_kubelet, mounted /var/lib/kubelet, and then tried to mv /var/lib/old_kubelet/* /var/lib/kubelet.

It turns out there are many (20ish) mount points underneath /var/lib/kubelet.

So when I tried to move or copy, it actually tried to copy the contents of those mount points!

What’s the easy and safest way to move the contents without copying the child mount points?

Other probably irrelevant information: the block device that the mount point should be pointing to is a LUKS volume